Printing telegraph apparatus



1944. w. J. ZENNER 7 HUNTING TELEGRAPH APPARATUS Filed April 17, 1942 IN VENTOR.

5 ATTORNEY.

Patented Jan. 4, 1944 2,338,275 PRINTING TELEGRAPH APPARATUS Walter J. Zenner, Des Plaines, -Ill., assignor to Teletype Corporation, Chicago, 111., a corporation of Delaware Application April 17, 1942, Serial No. 439,357 6 Claims. (Cl. 17834) The present invention pertains to printing telegraph apparatus and particularly to the control of recorders responsive to isochronous code si nals.

The principal object of the present invention is to provide an efiicient printer of simple construction, operable upon the start-stop principle and having as a salient feature an orientation arrangement of novel construction.

In accordance with the present invention, the line signal for each character consists of a nocurrent starting impulse and a current definitive impulse. In the event that signal elements of 0pposite polarity are employed, the starting impulse will be of positive or negative current, and the definitive impulse will be of a negative or positive nature, respectively. Specifically, each code signal is composed of two signal elements, in which each signal element occurs but once in a code signal. The sum of the lengths of the elements in each code signal is constant, and although each element varies in length in each code signal, nevertheless each element in each code signal is the complement of the other element of that particular code signal. Thus, each signal is formed, and each character is determined, by the relative lengths of the elements composing the code signal.

Upon the reception of the starting impulse, a selector magnet, which is normally energized inasmuch as the idle condition of the line is of marking or current nature, releases its armature to control a power clutch, and thereby permits a type wheel to rotate in phase with a controlling element in a remote transmitter. During the rotation of the type wheel, the selector magnet, upon the termination of the starting impulse, which occurs simultaneously with the beginning of the definitive or stop impulse of opposite polarity or current condition, again becomes energized and attracts its armature.- Thisaction serves, in the preferred form of the present invention, to actuate a ratchet Wheel and effectprinting through a camming action produced by the engagement of a printing arm with the pe-- riphery of the ratchet wheel, whereby printing is effected at the instant when the reversal of signaling condition occurs in the code signal.

cycle.

The orientation device, according to the present invention provides an invariable latching area of "bite between the type wheel stop armand the selector magnet controlled stop lever, whereby uniform effectiveness between the stop arm and stop lever is maintained in all orientation or phasing positions.

A more complete understanding of the invention may be had from the following description taken in conjunction with the accompanying drawing, wherein like reference characters desig-' nate similar parts throughout the several views, and in which,

Fig. 1 is an elevational view of the printing apparatus according to the present invention, show-' Fig. 4 is a graphical representation of a signal of the monopulse type employed in operating the printer according to the'present invention; and

Fig. 5 is afragmental detail view of the printingleven Monopulse' signals may be composed, as previously indicated, of'current and no-current sig-} nal conditions, and as may be understood by referring to Fig. 4, the transmission of monopulse signals of the type contemplated involves the interruption of a normal line'condition for a measured interval which is initiatedat a point definite with respect to each transmission cycle and is'oontinu'ed until the transmitter has at-' tained a position in the cycle which corresponds to, and is identified with, the particular character transmitted. At the termination of this impulse, normal line current condition is restored,

as indicated at the character Win Fig. 4. Normal line current is maintained thereafter until the arrival. of the succeeding start instant, when, if a succeeding character is in readiness for transmission, another repeated;

Having reference to Fig. l, the framework of plate I I and a base plate l2 rigidly united thereto by angle iron brackets l3. Mounting pads M are secured to the bottom'side of the base plate l2. regulated motor (Fig. 3) I5 is mounted upon a the printer comprises a front bracket I6 which is fixed to the front'plate H.

A pinion I1 is secured to the armature shaft I3 gear l9, forming the driving member of a friction clutch mb y 2| on a start-stop shaft 22 suitably Gear I9 is frictionally' 22 by means of the friction clutch assembly 2|, comprising a pair of annular friction discs 23 and 24, compressed between of the motor l5, and meshes with a journaled in the printer. associated with shaft line interruption is thereat collar secured to shaft 22 and a disc 26 carried on said shaft, compressive force being supplied by spring 21, which at one end presses against disc 26 and which is restrained at its other end by an adjustable collar 28 attached to the shaft 22 (as viewed in Fig. 3). A type wheel 3| is secured by screws 32 to the flange 33 of a sleeve member 34 fixed to the shaft 22. Integral with the sleeve 34 is a spacing cam 35 and a stop arm 36 (Fig. 1). Fixed to the sleeve member 34 is an index wheel 31 which cooperates, as will presently appear, with a stabber or indexing element 38 to locate the type wheel accurately in the printing position when a character is printed.

Stop arm 36 coperates with a'stop lever 4| pivotally mounted at 33 on a plate 42. Plate 42 comprises a part of the orientation arrangement according to the present invention and is adjustable in correspondence with the orientation position desired for the stop arm 35. Orientation plate 42 is provided with a slot 43 of arcuate conformation concentric with the shaft 22, and cooperating with the slot 43 is a clamping screw 44. Plate 42 is also provided with an integral index arm or pointer 45 which cooperates with a series of registration marks or graduations 4B etched in the plate Stop lever 4| normally tends to rotate in a counterclockwise direction (as viewed in Fig. 1) under the influence of a spring 41 extending from the end of the vertical arm of lever 4| to a spring post on the stop plate 42. An adjustable eccentric back stop 48 is provided to limit the counterclockwise rotation of stop lever 4|. Stop lever 4| is provided with a laterally projecting lug 49 which cooperates with the outer extremity of stop arm 35. Also, lever 4| terminates in a cam surface 5| which cooperates with a follower member 52 carried at the upper extremity of an armature lever, indicated generally as 53. The contour of cam surface 5| is such that, when lever 4| assumes its clockwise position, said cam surface is concentric with shaft 22. The adjustable element 52 is in the form of an eccentric screw to adjust the cooperative relationship between armature lever 53 and stop lever 4|.

Armature lever 53 is pivotally mounted in an appropriate manner on the front plate H and is provided with a pole piece 54. Cooperatively associated with the pole piece 54 is a selector magnet 55 which is mounted on a bracket 56 secured to the inside surface of plate H. Armature lever 53 is dually controlled, on the one hand by the selector magnet 55' and on the other hand by a spring 51 extending between the armature lever 53 and a spring post 58 on the plate An eccentric back stop 59-is provided to limit the clockwise movement of the armature lever 53 under the influ'ence'of spring 51. Pivotally carried near the upper end of armature lever 53 is a pawl member 6| which cooperates with a ratchet wheel 52 rotatably carried on a shaft 53 suitably journaled in the plate The pawl 5.! is normally biased in a counterclockwise direction, to maintain the pawl 5| in cooperative engagement with the teeth on the periphery of the ratchet wheel 62, by means of' va spring 3-4 extending between the pawl member 5| and. the armature lever 53. Also cooperating with the ratchet wheel 6-2 is the downwardly projecting end 55 of a lever 66 pivotally mounted on astud shaft 61 secured to the plate ll. Lever 55 is normally biased in a clockwise direction by a spring 63 extending between lever 56 and a spring post 69 of the plate Lever 65 also magnet carries the afore-mentioned stabber element 33 which cooperates with the index wheel 31. Also carried on the stud shaft 51 and c-ooperablc yieldably with lever is the print hammer 1| which is provided at its extremity or free end with a laterally extending platen portion 12 (more clearly shown in Fig. 3). Print hammer 1| is provided with an upstanding portion 13 at the extremity of which is connected one end of a spring 14 the other end of which is connected to lever 65. Counterclockwise rotation is thus normally imparted to hammer 1| with respect to pivot 61 by the spring 14. Hammer 1| (as shown in Fig. 5) is provided with a slot 15 which cooperates with the eccentric shoulder portion of an adjusting screw 15. With this arrangement, lever 56 and hammer 1| move as a unit about the pivot 51 during the printing operation (to be presently described) until the platen 12 strikes the character on the type wheel, after which a yield is provided by the spring 14, rendered effective by the slot and screw arrangement provided by members 15 and 16, so that no damage will be done to the print hammer 1| if too great a pressure is imparted by the ratchet wheel 62 to the downwardly projecting end 65 of lever 66.

When the armature lever 53 is oscillated upon the energization and de-energization of selector in response to the character signal received, the pawl 6| is moved rightwardly (as viewed in Fig. 1) upon the de-ene'rgization of magnet 55 by the spring 51 to pick up the next tooth on the ratchet wheel 52, whereupon, when the selector magnet 55 is energized by marking current on the signal line, the armature 53 will be attracted, and the pawl 6| will be actuated leftwardly to cause a predetermined angular movement of the ratchet wheel 62. As a result of this angular movement of ratchet wheel 52, in a counterclockwise direction, the lever 35 will be rocked counterclockwise due to the cooperation of the downwardly projecting end 55 and the teeth of the ratchet wheel 62 whereby the lever will be cammed counterclockwise upon each angular or stepwise movement of the ratchet wheel causing the upwardly projecting lug 38 to cooperate with a notch in the index wheel 31 and at the same time bringing the platen 12 into cooperative engagement with the type wheel 3|, and should greater movement be imparted to lever 66 than would under certain conditions of adjustment be permitted by the platen 12, the yield (Fig. 5) provided between lever 56 and hammer 1| will prevent any damage being done to the mechanism.

Cooperating with the spacing cam 35 is a spacing bell crank 8| which is pivotally carried on a pivot 82 secured to plate M (Fig. 2). To arm 83 of spacing lever 8| is connected one end of a spring 84 the other end of which is connected to a spring post 85 mounted on the plate I At the extremity of arm 85 of spacing lever 8| is pivoted a pawl member 81 which cooperates with a spacing ratchet wheel 88 carried on a stud shaft 83 journaled in the plate I Normal counterclockwise rotation is imparted to the pawl 31 by a spring 9| extending between pawl 81 and a lug on arm at of spacing lever 81. Thus, as the spacing cam 35 rotates, it tends to rock the spacing lever 8| counterclockwise about pivot 32 thereby mov ing the pawl 81 in such a manner as to pick up a tooth in a clockwise direction about the ratchet 88. Then, as cam 35 in its clockwise movement (as viewed in Fig. 2) reaches a point where the arm 83' approaches the drop-01f in the cam, spacing lever 8| will be actuated sharply in a clockwise direction by its spring 84, thus causing the pawl 8! to actuate the ratchet wheel 88 one angular step in a counterclockwise direction. Detent spring 90 acts to hold ratchet 88 against reverse or clockwise rotation when pawl 81 operates to pick up the next tooth and prevent overtravel.

Also carried on the stud 89 is a tape feed roller 92 which is provided with a pair of flanges to serve as guides for the tape 93. A pressure roller 94 cooperates with the feed roller 92 and is normally biased in a counterclockwise direction (as viewed in Fig. 1) about its pivot 95 by a spring 96 extending between the pressure roller arm 91 and a spring post 98 carried on the plate The tape 93 is suitably guided through the printing zone by a guide way 99 (Fig. 2).

General operation In the operation of the printer mechanism just described, the motor I is constantly rotating at a speed commensurate with the speed of rotation of the transmitting apparatus, which may be of the type disclosed in U. S. Patent No. 2,173,147 issued September 19, 1939, to Walter J. Zenner. As indicated in the diagram shown in Fig. 4, the normal condition of the line is marking; that is, there is current on the signal line which maintains the selector magnet 55 normally energized. Under this condition, the armature lever 53 is held attracted by the selector magnet 55 against the pull of the spring 51. While the armature lever 53 is thus held attracted, its upper extremity, through the instrumentality of the adjustable cam follower element 52, acts to hold the stop lever 4| in its clockwise position with the stop lug 49 thereon in the path of the stop lever 35. Through the pinion ll on the motor shaft, the motor l5 imparts continuous rotation to gear I9, but through the frictional clutch 2| on shaft 22, stop arm 35 is held against the latching shoulder 49 on the stop lever 4|. Thus, during cessation of signal reception by the printer, the stop lever 4| is held in latching engagement with the stop lever 36 by the armature lever 53 of the selector magnet 55.

In accordance with the present invention, an orientation device has been provided which may be used to bring the printer mechanism into exact phase relation with the signals transmitted by a transmitter such as disclosed in the aforementioned Zenner Patent 2,173,147. Due to the nature of the isochronous monopulse code signal employed in controlling the operation of the form of printer according to the present invention, the commencement of the start impulse causes the selector magnet 55 to be de-energized and permits spring 57 to actuate armature lever 53 to its rightward position against stud 59. In response to this movement of lever 53, stop lever 4| is retracted from the path of stop arm 36 by spring 41, permitting shaft 22 and the elements fixed thereon to rotate. At the instant in the cycle of rotation of shaft 22 determined by the particular character to be printed and evidenced by a reversal of the current in the line, the magnet 55 becomes energized and immediately effects the movement of lever 53 in a counterclockwise direction thus causing, due to the camming action of ratchet wheel 62 upon pawl 6|, the platen 12 to rise and press the tape 93 against the type character on the type wheel, the stabber 38 cooperating with stop wheel 31 to index or stop the type wheel momentarily for printing.

It is necessary that the type wheel 3| starts to rotate at the instant when the start signal is received, and that when the reversal in the monopulse signal occurs, it is further necessary that the character registering with the printing point (exemplified by the platen 12) correspond exactly and be correctly positioned with respect to the signal identified with the character sent out by the transmitter. To assure this exact operation, the orientation arrangement according to the present invention is provided. In achieving this result, the clamping screw 44 is loosened and the orientation plate 42 is rotated through the instrumentality of arm 45 until the proper relation between the starting point exemplified by the coaction between the stop arm 36 and the stop lug 49 is properly adjusted with respect to the printing point exemplified by the platen I2. When this point has been attained, the clamping screw 44 is again tightened and the particular indication 46 for this particular printer is noted.

It is very important that the area of engagement or bite between the stop arm 35 and the lug 49 be a fixed and invariable amount in all positions of adjustment of the orientation plate 42. Such a condition has not been attained or accomplished by prior devices, but with the present invention an invariable latching area or bite between the type wheel stop arm 36 and the selector magnet controlled stop lever 4| is maintained for all positions of the orientation plate 42. To achieve this result, the present invention provides a stop lever 4| having a specially contoured cam surface 5| which cooperates with the adjustable element 52 carried on the end of the armature lever 53'. The contour of the camperiphery or surface 5| is such that irrespective of the rotative position of the orientation plate 42, the latching area between the end of arm 36 and projection 49 remains unchanged. That is, the locus of cooperation between arm 36 and projection 49 remains concentric about the shaft 22 and the cam surface 5| has been so constructed that, with the adjustable element 52 held in its leftward position, said cam surface is substantially concentric with shaft 22 and the contact between cam surface 5| and element 52 will be such as to maintain said latching area constant in its travel along the concentric path about shaft 22, which travel results from adjusting the angular position of Elsie orientation plate 42 by means of its arm After the proper orientation condition has been established and the start signal is received, the

magnet 55 will be de-energized and the arma ture lever 53 will be actuated clockwise by spring 51 to permit spring 41 to actuate lever 4| to its counterclockwise position against stud 48. During this operation pawl 6| has been moved rightwardly to pick up the next tooth in a clockwise direction about the ratchet wheel 62 so that when the selector magnet 55 is again energized, upon receipt of the marking portion of the monopulse code signal, the armature 53 will be actuated or attracted so that the pawl 9| will rotate the cam 62 angularly one step in a counterclockwise direction. In response to this counterclockwise angular rotation of ratchet wheel 62, the lever 66 is actuated counterclockwise through the instrumentality of the depending portion to bring the platen 12 into printing action with the type wheel (H with the tape 93 interposed therebetween. However, just prior to the engagement of platen 12 with type wheel 35, stabber 3E cooperates with index wheel 31 to locate the type wheel accurately in the printposition. 1111; is supplied to the type wheel 3| by means of the usual form of ink roller IM, as indicated in Fig. 3. A yieldable means previously described between the lever (56 and the print hammer H insures proper printing engagement between the platen l2 and the type wheel 31. Of course, when the armature 53 is attracted by the selector magnet 55 in response to the marking portion or definitive impulse of the monopulse signal, the stop lever 4! is returned to its clockwise position, shown in Fig. 1, to bring lug is again into latching relation with the stop arm 36.

Ihe present invention has been disclosed in connection with a certain specific embodiment thereof, but it is contemplated that such em bodiment is merely illustrative, and that all forms coming within the scope or range of equivalency of the appended claims are intended to be covered herein.

What is claimed is:

1. In a recording device, a start-stop shaft having an arm fixed thereto, start-stop control means for said shaft having a predetermined extent of engagement with said arm, printing means, a single magnet responsive to electrical signaling conditions for controlling said printing means, means effective as an incident of the control of said printing means for controlling said start-stop control means, and means carrying said start-stop control means for orienting said control means about said shaft without varying the extent of said engagement.

2. In a printing telegraph receiver, a startstop shaft, an arm fixed to said shaft, a normally energized magnet, a printing means, control means having a predetermined extent of engagement with said arm responsive to the deenergization of said magnets for releasing said shaft for rotation, means effective upon re-energization of said magnet for controlling the operation of said printing means, and cam means cooperating with said control means to maintain the cooperation between said control means and said stop arm invariable in any position of said orientation device.

3. In a telegraph recorder, a type wheel, a type wheel shaft, means constantly tending to rotate said type wheel shaft, a stop arm carried by said type wheel shaft, a stop lever cooperating with said stop arm, an orientation plate rotatably mounted on said type wheel shaft, said stop lever pivoted on said plate, means responsive to receiver signals, printing means controlled by said signal responsive means, and cam and follower means associated with said stop lever and said printing means, respectively, whereby orientation adjustment can be effected without altering the latching area between said stop arm and said stop lever.

4. In a telegraph receiver, a type wheel, a type wheel shaft, means constantly tending to rotate said type wheel shaft, a stop arm carried by said type wheel shaft, a stop lever cooperating with said stop arm in a manner whereby a predetermined area of engagement is established between said stop arm and said stop lever, an orientation plate rotatably mounted on said type wheel shaft, said stop lever pivoted on said plate, means responsive to received signals, printing means controlled by said signal responsive means, and cam and follower means associated with said stop lever and said printing means, respectively, whereby orientation adjustment can be effected without altering said area of engagement.

5. In a telegraph receiver, character carrying means, a start-stop arm associated with said means, a latching lever cooperating with said arm in a manner whereby a predetermined area of engagement is established between said arm and said lever, an orientation plate rotatably mounted concentrically with said means and adapted to pivotally support said latching lever, means responsive to received signals, printing means controlled by said signal responsive means, and cam and follower means associated with said latching lever and said printing means, respectively, whereby said area of engagement remains invariable in all positions of said orientation plate.

6. In a telegraph receiver, a character carrying member, a shaft therefor, a start-stop arm associated with said member, a latching lever cooperating with said arm in a manner whereby a predetermined area of engagement is established between said arm and said lever, an orientation plate rotatably mounted concentrically with said shaft and adapted to pivotally support said latching means, means responsive to received signals, printing means controlled by said signal responsive means, and cam and follower means associated with the stop lever and said printing means, respectively, whereby the locus of said cooperation between said stop lever and stop arm remains concentric about said shaft and said area of engagement remains invariable at all points on said locus.

WALTER J. ZENNER. 

